Development of cholinergic chronotropic control in chick (Gallus gallus domesticus) embryos
Development of cholinergic chronotropic control in chick (Gallus gallus domesticus) embryos
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DOI：
10.1016/s1095-6433(03)00271-x
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发表时间：
2004-01-01
影响因子：
2.3
通讯作者：
Tazawa, H
中科院分区：
文献类型：
--
作者：
Chiba, Y;Fukuoka, S;Tazawa, H
在小鸡（Gallus Gallus驯化）胚胎中，瞬时心率开始波动，在孵化的第二周结束时出现快速，短暂的减速。先前的研究表明，在胚胎晚期，施用阿托品可以消除瞬时心率减速，同时心率基线升高。由于先前的研究缺乏统计学处理，并且最近对心脏的强直性迷走神经控制的发展存在争议，因此我们重新研究了瞬时心率的短暂性减慢是由迷走神经介导的，迷走神经张力在潜伏期第二周左右开始出现。阿托品;共对67个11 ~ 14日龄和18日龄的胚胎进行了给药试验。10个12日龄胚胎中有3个出现偶发性心率减慢，但给药前后模式心率差异不显著。9个137日龄胚胎中有7个和9个14日龄胚胎均出现心率减慢，阿托品给药前后模式心率差异显著。在晚期（18日龄）胚胎中，瞬时的幅度和频率。心率减速进一步增加，同时出现短暂的不规则加速。施用不同剂量的阿托品完全消除了心率减速，并比年轻胚胎更明显地提高了心率基线，表明迷走神经张力在孵育后期成熟。(C) 2003 Elsevier Inc.版权所有。
In chick (Gallus gallus domesticus) embryos, instantaneous heart rate begins to fluctuate with the appearance of rapid, transient decelerations at around the end of the second week of incubation. Previously, it was shown that instantaneous heart rate decelerations were eliminated by administration of atropine and concurrently heart rate baseline was elevated in late embryos. Because the previous study lacked statistical treatment and there has been recent controversy over the development of tonic vagal control of the heart, we reexamine the hypothesis that transient decelerations of instantaneous heart rate are mediated by vagus nerve and the vagal tone begins to appear at around the end of the second week of incubation. Atropine; administration tests were conducted for sixty-seven 11- to 14-day-old and 18-day-old embryos in total. Heart rate decelerations appeared sporadically in three out of ten 12-day-old embryos, but the difference of mode heart rate before and after administration of atropine was not significant. Seven out of nine 137day-old embryos and all nine 14-day-old embryos showed heart rate decelerations and the difference of mode heart rate before and after atropine administration was significant. In late (18-day-old) embryos, magnitude and frequency of instantaneous. heart rate decelerations further increased with additional appearance of transient, irregular accelerations. Administration of varying doses of atropine completely eliminated the heart rate decelerations and elevated the heart rate baseline more markedly than in young embryos, indicating the maturation of vagal tone late in incubation. (C) 2003 Elsevier Inc. All rights reserved.